A year after China upended global materials markets by banning imports of much solid waste, the effects are still rippling around the globe. Many U.S. recyclers are awash in materials they formerly sent to China for processing. Some cities with few options are burning recyclables in incinerators.

What would it take to reduce U.S. waste management headaches? These five essential reads offer some insights.

1. Embrace the circular economy

Waste is inevitable when products are designed to be used and then thrown away. Clyde Eiríkur Hull, professor of management at Rochester Institute of Technology, offers an alternative: a circular economy in which products are used, then recycled and remanufactured into new products.

Major U.S. companies, including GM, Caterpillar and Staples, are saving money through recycling and remanufacturing. But Hull says this could be greatly scaled up if the federal government required products to be designed with future reuse in mind and taxed goods that did not comply.

“In an entirely circular economy, the U.S. would most likely still import stuff from abroad, such as steel from China. But that steel would wind up being reused in American factories, employing tax-paying American workers to manufacture new goods,” he writes.

2. Get serious about recycling plastic

Of all materials in the waste stream, plastics pose the biggest challenge. They are used in a myriad of consumer goods, including many single-use items such as straws and cutlery, and can take centuries to break down. Kate O'Neill, professor of global environmental policy at the University of California, Berkeley, compares plastic waste to J.R.R. Tolkien’s One Ring, which “can be permanently destroyed only through incineration at extremely high temperatures.”

O'Neill identifies a number of steps to boost plastic recycling in the United States. They include better consumer education about sorting and disposal; less reliance on single-stream collection, which mixes plastics with other materials; more investment in scrap processing facilities; and steps to manage specific plastic products that are hard to recycle, such as 3D printer waste.

3. Pursue plant-based plastics – and composting

Conventional plastics are derived from fossil fuel, but they can also be made from renewable biological compounds that break down more easily, such as plant sugars. A key challenge with these products is making items that are strong enough to hold up during use but still biodegradable.

“A straw and cup that disintegrate halfway through your road trip are not much use at all,” observes Michigan State University biochemist Danny Ducat, whose lab is using photosynthetic bacteria to synthesize bioplastic feedstocks.

Bioplastics also require investments at the end of their life cycles, Ducat notes. Like other plant-based materials, such as food scraps, they will only degrade readily in composting facilities, where microbes break them down in the presence of oxygen. Buried in landfills, they will persist for decades or centuries, much like conventional plastics. They also are likely to persist if they end up in other cold places with little oxygen, such as the Arctic or deep ocean waters.

“This means that any breakthroughs in materials science need to be coupled with sustainable methods for bioplastic production and a well-oiled system to direct bioplastic goods into composting facilities,” Ducat writes.

4. Recycle more steel and aluminum

Recycling is much more developed for metals than it is for plastics. In the United States, about 65 percent of old steel products and 40 to 65 percent of discarded aluminum products are recycled. But Daniel Cooper, assistant professor of mechanical engineering at the University of Michigan, asserts that more could be done.

As Cooper explains, the United States exports or throws away a lot of cheap scrap metal, and imports expensive new metal. “As an already industrialized country, the U.S. needs little new metal to meet domestic demand,” he points out. More federal support for metals recycling, he asserts, could slash new steel and aluminum imports.

In addition to saving the money and resources that go into producing new metals, such a policy would cost Americans much less than the tariffs President Donald Trump has imposed on imported steel and aluminum.

5. Reconsider waste incineration

Is burning trash instead of recycling it such a bad thing? Bucknell University economist Thomas Kinnaman thinks it’s worth a new look.

As Kinnaman acknowledges, waste incineration is much less popular in the United States than in other regions, including Japan and western Europe. Early U.S. waste combustion plants generated high levels of air pollutants, including hazardous substances such as dioxins, and often were sited in low-income and minority communities.

Incineration still has clear disadvantages. It’s more expensive than landfilling, and Kinnaman sees some evidence that once countries burn more than 40 percent of their waste, it starts to replace recycling. Nonetheless, he contends, expanding its use in the United States – which currently burns less than 13 percent of its solid waste – could be more socially responsible than shipping plastic scrap to developing countries that are ill-equipped to dispose of it.

Editor’s note: This is a roundup of previously published stories.

Jennifer Weeks, Environment + Energy Editor, The Conversation

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Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to This email address is being protected from spambots. You need JavaScript enabled to view it..

Birds are some of the most attractive creatures on earth. Who doesn’t like to watch a Blue Jay, Cardinal or Baltimore Oriole going about its business?

But the beauty of birds isn’t just their looks – it’s also their noises. Bird songs are among nature’s most distinctive and musically satisfying sounds. Why do birds spend so much time and energy singing?

There are two main purposes, and they are connected. First, male birds sing to mark territories. A singing bird is saying, “This place is mine, and I’m willing to defend it, especially from others of my species.” He may patrol his chosen space and sing often, either from the middle or the edges of what he considers his turf.

The second purpose of singing is to attract a mate for nesting. Female birds often choose their mates based on some blend of visual and vocal cues. Even male birds with beautiful breeding-season plumage can have trouble finding mates if their songs don’t measure up.

Each bird species typically has its own unique song. That allows an individual bird to hear a song and recognize whether the singer is from its own species.

Birds are most vocal during nesting season. For example, in Florida where I live, Cardinals live year-round. They usually start singing in January, just a few weeks after the days begin to get longer. After the nesting period is over, birds sing much less and their territories break down.

Many species of North American birds migrate with the seasons instead of staying in one place all year. As they fly south in the fall, they make little “chip” notes or “contact calls” that allow them to stay in touch with other birds.

In many species only male birds sing, but in others, both males and females sing. And some birds don’t sing at all. For example, vultures and storks can barely produce any sound – let alone something musical enough that we would call it a song.

Learning to identify birds by their songs is as much fun as spotting them by sight. In fact, good ears are often as important as good eyes in appreciating the birds you encounter. Take off your headphones and listen to your neighborhood birds – especially when they are active in the morning or evening. You’ll be surprised by what you hear.

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Please tell us your name, age and the city where you live. We won’t be able to answer every question but we will do our best.

David Steadman, Curator of Ornithology, Florida Museum of Natural History, University of Florida

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080819 Clearlake City Council agenda packet by LakeCoNews on Scribd

As an environmental scientist, I’ve done plenty of hiking in the western U.S. – always with a map, water bottle and list of water sources. In dry areas it’s always smart to ration water until you get to a new source. Sometimes a stream has dried up for the season, or a pond is too scummy to drink from, so your supply has to stretch further than planned.

On one memorable hike, I found that a water source was dry. The next one, three miles later, was dry too. And the one after that had a dead bear carcass in it. While one dry water source was tolerable, several in a row created a serious problem.

Something similar is happening to snow resources in the western United States. Scientists have long known that the warming temperatures associated with climate change are diminishing the region’s snowpack, with more precipitation falling as rain, rather than snow. That’s a problem because snowpack is a critical resource, acting as a natural reservoir that stores winter precipitation.

In a newly published study, my colleagues John Abatzoglou, Timothy Link, Christopher Tennant and I analyze year-to-year variations of future snowpack to see how frequently western states can expect multiple years in a row of snow drought, or very low snow. We find that if climate change continues relatively unabated, consecutive years with snow drought conditions will become much more common, with impacts on cities, agriculture, forests, wildlife and winter sports.

Snow droughts affect ecosystems and people

Snowpack is a critical resource in the western U.S. and Canada. Snow melts and runs off in spring and summer, when cities, farms and forests need water. It supports animals such as wolverines that depend on snow, and underpins winter sports industries.

Multiyear snow droughts are akin to drawing down a bank account for some of these important systems. For example, lower snow years typically have longer summer periods with low soil moisture. Trees and other plants may be able to survive these stresses for one year, but longer stretches could lead to increases in forest mortality.

These periods also test western reservoirs, many of which are managed for dual purposes: Storing spring runoff for times of high water demand, and holding space for potential floodwaters. The amount of space allocated to storage versus flood control varies by time of year.

Water managers may need to update these rules to account for higher chances of snow drought or changes in the timing of snowmelt runoff. Rainfall is also a factor, and at least in California, total precipitation is projected to become increasingly variable from year to year with climate change.

Snow droughts also affect the winter tourism industry. Ski resorts in lower-elevation areas with increasingly warm winters may be able to survive one year of poor snow conditions, but multiple low-snow years in a row may threaten their viability.

Projecting future snows

In our study we defined snow droughts as years with snowpack low enough to have historically occurred only one out of every four years or less. Such events occurred recently in the Sierra Nevada between 2012-2015 and the Cascades in 2014-2015.

Researchers created the dataset we used by first running 10 global climate models – computer programs that simulate historical and future climate based on a number of factors, including atmospheric carbon dioxide concentrations.

Like all climate projections, our estimates include some uncertainty. Each global climate model produces slightly different results; by analyzing all 10, we can be more confident in our conclusions when most of them agree on projected changes.

These models produce data with a resolution of hundreds of kilometers. That doesn’t provide detailed information about conditions in the mountainous parts of the western U.S., where conditions vary dramatically over much smaller scales. To solve this problem, the modelers used a process called downscaling to develop results with much higher spatial resolution – in this case, to grid cells that measured about six kilometers on a side.

Then they loaded this climate data into a hydrologic model that estimates daily snow accumulation and melt. We used the results from this hydrologic model to calculate changes in snowpack in future conditions, relative to historical conditions.

Fewer big snow years

Today, back-to-back snow droughts in the western U.S. occur around 7% of the time. By mid-century, if greenhouse gas emissions continue to increase, our results predict that multiyear snow droughts will occur in 42% of years on average.

In addition to projecting more frequent snow droughts, we also found that peak snowpack is projected to decline and become less variable in a warming climate across much of the mountainous West. This will mean there will be fewer very high-snow years to offset the impacts of low-snow years.

Another feature of changing snowpack is the timing of when it accumulates and melts. Generally, as the climate warms snow is melting earlier, which leads to earlier spring runoff and less water available in summer.

In our study, we also found that in many places the timing of peak snowpack is projected to become more variable from year to year. We developed an interactive tool that allows users to explore this data on their own.

Planning for the future

Our results are based on a future in which the world continues to rely on fossil fuels. Reducing greenhouse gas emissions would limit the impacts on western snowpack that we project.

On the hike where all of my water sources were dry, I was saved by a kind stranger. The trail intersected a road, and a passing driver gave me some water. Global climate change won’t be solved so easily: Addressing these issues will require major coordinated efforts to limit future warming and manage Earth’s natural resources strategically to provide for society’s needs and environmental conservation.

Adrienne Marshall, Postdoctoral Fellow in Forest, Rangeland, and Fire Sciences, University of Idaho

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